Argentotetrahedrite

Argentotetrahedrite is a rare mineral belonging to the tetrahedrite group. It is a sulfosalt mineral with the chemical formula (Ag,Cu)10(Fe,Zn)2(Sb,As)4S13. The presence of significant silver, indicated by the "argen-" prefix, is a defining characteristic. It is isostructural with tetrahedrite and tennantite, meaning it shares the same crystal structure. The mineral crystallizes in the isometric system, typically forming small, tetrahedral or dodecahedral crystals, though massive or granular aggregates are also found. Its color is typically dark gray to black, and it possesses a metallic luster. Argentotetrahedrite is relatively soft, with a Mohs hardness of around 3 to 3.5, and has a high specific gravity due to the presence of silver. It is an opaque mineral. Argentotetrahedrite is primarily found in hydrothermal veins and disseminated deposits, often associated with copper and silver ores. It can form during the later stages of hydrothermal activity. Notable occurrences include mines in Mexico, Peru, and the United States. Due to its rarity and composition, argentotetrahedrite is of interest to mineral collectors and is considered a minor ore of silver. It is not a widely abundant or economically significant mineral compared to other silver-bearing minerals.